Hydrant cap leak detector with oriented sensor

Abstract

A nozzle cap includes a cap body defining a cap axis, the cap body defining a circumferential wall extending circumferentially around the cap axis; and a vibration sensor including a shaft, the shaft defining a first end and a second end, the first end attached to the circumferential wall, the cap axis positioned closer to the second end than to the first end.

That which is claimed is: 
     
       1. A nozzle cap comprising:
 a cap body defining a cap axis, the cap body defining a circumferential wall extending circumferentially around the cap axis; and 
 a vibration sensor comprising a shaft, the shaft defining a first end and a second end, the first end attached to the circumferential wall, the cap axis positioned closer to the second end than to the first end. 
 
     
     
       2. The nozzle cap of  claim 1 , wherein the shaft is defined by a fastener of the vibration sensor. 
     
     
       3. The nozzle cap of  claim 2 , wherein the first end is a threaded end. 
     
     
       4. The nozzle cap of  claim 1 , wherein the vibration sensor further comprises at least one piezoelectric crystal positioned adjacent to the second end. 
     
     
       5. The nozzle cap of  claim 1 , wherein the vibration sensor further comprises at least one calibration mass positioned adjacent to the second end. 
     
     
       6. The nozzle cap of  claim 1 , wherein a spacer is positioned between the first end and the second end. 
     
     
       7. The nozzle cap of  claim 1 , wherein the shaft defines a sensor axis extending from the first end to the second end, and wherein the sensor axis extends radially inward with respect to the cap axis. 
     
     
       8. The nozzle cap of  claim 7 , wherein the sensor axis is perpendicular to the cap axis. 
     
     
       9. The nozzle cap of  claim 1 , wherein the circumferential wall defines a cavity, wherein the nozzle cap further comprises a printed circuit board positioned in the cavity, and wherein the printed circuit board is connected in electrical communication with the vibration sensor and an antenna. 
     
     
       10. A hydrant assembly comprising:
 a fire hydrant comprising a barrel and a nozzle extending outwards from the barrel; and 
 a nozzle cap comprising:
 a cap body mounted on the nozzle, the cap body defining a cap axis, the cap body defining a circumferential wall extending circumferentially around the cap axis; and 
 a vibration sensor comprising a shaft, the shaft defining a first end and a second end, the first end attached to the circumferential wall, the cap axis positioned closer to the second end than to the first end. 
 
 
     
     
       11. The hydrant assembly of  claim 10 , wherein the shaft is defined by a fastener of the vibration sensor. 
     
     
       12. The hydrant assembly of  claim 11 , wherein the first end is a threaded end. 
     
     
       13. The hydrant assembly of  claim 10 , wherein the vibration sensor further comprises at least one piezoelectric crystal positioned adjacent to the second end. 
     
     
       14. The hydrant assembly of  claim 10 , wherein the vibration sensor further comprises at least one calibration mass positioned adjacent to the second end. 
     
     
       15. The hydrant assembly of  claim 10 , wherein a spacer is positioned between the first end and the second end. 
     
     
       16. The hydrant assembly of  claim 10 , wherein the shaft defines a sensor axis extending from the first end to the second end, and wherein the sensor axis extends radially inward with respect to the cap axis. 
     
     
       17. The hydrant assembly of  claim 16 , wherein the sensor axis is perpendicular to the cap axis. 
     
     
       18. The hydrant assembly of  claim 10 , wherein the circumferential wall defines a cavity, wherein the nozzle cap further comprises a printed circuit board positioned in the cavity, and wherein the printed circuit board is connected in electrical communication with the vibration sensor and an antenna.